The day the Earth moved
SEOUL — New radar satellite images show the Sept. 3 nuclear test by North Korea was powerful enough to sink a roughly 35-hectare area on the peak of a mountain above the tunnels where the test likely took place.
North Korea carries out its nuclear tests in a complex of tunnels at its Punggye-ri site and images of the mountains, in this case Mount Mantap, above it can give experts a sense of where the device was tested exactly and how powerful it was.
The new Synthetic Aperture Radar satellite images, captured before and after Sept. 3, showed “significant changes at Mantap’s peak elevation.
Prior to the test, Mantap was 2,205 metres high; the mountain has since diminished in height,” wrote Jeffrey Lewis, head of the East Asia program at the James Martin Center for Nonproliferation Studies in California.
“You can see that the explosion visibly displaces the mountain, which demonstrates both how large the explosion was but also that it occurred in the same tunnel complex as the preceding four nuclear tests,” Lewis wrote on the Arms Control Wonk website. “This is useful because the relationship between the size of the explosion and the magnitude of the seismic signals is sensitive to the overburden — how much rock is above the explosion.”
The images were taken by Airbus, a space technology company that makes earth observation satellites, using its TerraSAR-X satellite, and provided to experts at the centre.
The device, which North Korea described as a hydrogen bomb capable of being placed on a ballistic missile, was the most powerful tested to date.